Because low doses of recombinant alpha interferon are very effective in the treatment of patients with hairy cells leukemia, this study was designed to determine if equally low doses of alpha interferon were effective in another indolent B-cell neoplasm, favorable histology non-Hodgkin's lymphomas. We also wish to determine the effects of recombinant alpha interferon in low doses in patients with the T-gamma lymphoproliferative disorder, a disease of T-cells that resembles in many regards hairy cell leukemia. Thirty-six patients with favorable histology chemotherapy- resistant non-Hodgkin's lymphoma were randomized, sixteen to the low-dose arm of the study (3 million/units qd) and twenty to the high-dose arm of the study (50 million units I.M. biw). The overall response rate is 26 percent with equal percentages of responders in each arm of the study. Of six patients with the T- gamma lymphoproliferative disorder, none have had an obvious antitumor response. However, one patient with pure red cell aplasia no longer has absence of red cell precursors in this marrow and no longer is requiring transfusion support.